Respiratory protection - 688 entries found
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Coffey C.C., Campbell D.L., Myers W.R., Zhuang Z., Das S.
Comparison of six respirator fit-test methods with an actual measurement of exposure in a simulated health care environment: Part 1 - Protocol development; Part 2 - Method comparison testing
While quantitative fit tests (QNFT) have been assumed to be predictive of the protection provided by respirators, studies have consistently found no correlation between quantitative fit factors and workplace protection factors. A study was designed to compare the fit factors from six QNFT methods against the actual dose of 1,1,2-trichloro-1,2,2 trifluoroethane (Freon-113) received under the same laboratory conditions. Results suggest that some QNFT methods may be used to estimate actual respirator performance under laboratory conditions. Topics: 1,1,2-trichloro-1,2,2-trifluoroethane; comment on standard; comparative study; determination in exhaled air; evaluation of technique; exposure evaluation; leakage testing; personal sampling; respirators; skin absorption.
American Industrial Hygiene Association Journal, Dec. 1998, Vol.59, No.12, p.852-870. Illus. 50 ref.
Protective gloves for handling hazardous substances
Schutzhandschuhe beim Umgang mit Gefahrstoffen [in German]
An improved test method for determining the permeability of protective gloves is described. It takes into account the following facts which affect permeability: 1. most protective gloves on the market are made of layers of different materials; and 2. mixtures of harmful substances are handled more often than single substances. In addition, the method takes into account wear and repeated contact with harmful substances. It closes the gap left by present methods which determine the penetration resistances of gloves made of a single material in contact with a pure substance. Topics: construction work; harmful substances; liquid-penetrant testing; materials testing; mixtures; penetration resistance; permeability testing; protective gloves; service life; technical development.
Sicherheitsingenieur, Mar. 1998, Vol.29, No.3, p.28-32. Illus.
Myers W.R., Zhuang Z.
Field performance measurements of half-facepiece respirators: Steel mill operations
Ambient and in-facepiece air samples were collected in different areas of a steel mill. Protection was assessed by workplace protection factors (WPF). All the in-facepiece concentrations were considerably less than the corresponding ambient concentration levels or permissible exposure limits. Mean ambient and in-facepiece concentrations of iron varied among tasks. Significant differences in respirator performance as measured by WPF or in-facepiece iron concentration were observed among the different brands of respirators. Topics: air sampling; airborne dust; iron; determination in air; evaluation of equipment; exposure evaluation; iron and steel industry; job-exposure relation; particulate removing respirators; personal sampling; protection criteria; respirators; steelworks; threshold limit values.
American Industrial Hygiene Association Journal, Nov. 1998, Vol.59, No.11, p.789-801. Illus. 27 ref.
Respiratory protective equipment (RPE) and protection levels
Topics: comment on standard; description of equipment; European Communities; particulate removing respirators; protection criteria; respirators; selection of equipment.
Safety and Health Practitioner, Sep. 1998, Vol.16, No.9, p.50-51. Illus. 16 ref.
Barrett L.W., Rousseau A.D.
Aerosol loading performance of electret filter media
Various types of flat sheet electret filter media were compared with mechanical filer media (fibre glass) using aerosol filtration tests designed for particulate respirators. Results revealed significant differences in filtration performance and loading behaviour among the various media. Respirators can be designed using electret filter media without sacrificing low pressure drop, light weight or user comfort. Topics: aerosols; collection efficiency; comparative study; electrostatic particulate filters; evaluation of equipment; filtration efficiency; respirable dust.
American Industrial Hygiene Association Journal, Aug. 1998, Vol.59, No.8, p.532-539. Illus. 17 ref.
Huang C., Willeke K., Qian Y., Grinshpun S., Ulevicius V.
Method for measuring the spatial variability of aerosol penetration through respirator filters
Topics: aerosol spectrometer; aerosols; air purifying respirators; description of technique; equipment testing; filter testing; filtration efficiency; particle size distribution; particle size; particulate filters.
American Industrial Hygiene Association Journal, July 1998, Vol.59, No.7, p.461-465. Illus. 17 ref.
Verma D.K., Pagotto J.G., Shaw D.S., Destombe K., Nieboer E.
Assessment of triethylamine and diethylamine emission from military gas mask canisters
Topics: diethylamine; triethylamine; defence services; determination in air; exposure evaluation; gas removing respirators; leakage testing; threshold limit values.
Annals of Occupational Hygiene, July 1998, Vol.42, No.5, p.325-330. Illus. 13 ref.
Aerosol penetration behavior of respirator valves
Topics: aerosols; comparative study; equipment testing; leakage testing; leakage; particle size; respirators; valves.
American Industrial Hygiene Association Journal, Mar. 1998, Vol.59, No.3, p.173-180. Illus. 14 ref.
Qian Y., Willeke K., Grinshpun S.A., Donnelly J., Coffey C.C.
Performance of N95 respirators: Filtration efficiency for airborne microbial and inert particles
Topics: airborne dust; comment on directive; evaluation of equipment; filtration efficiency; microorganisms; particle size; particulate removing respirators; respirators; USA.
American Industrial Hygiene Association Journal, Feb. 1998, Vol.59, No.2, p.128-132. Illus. 17 ref.
RPE - Building a healthy lifestyle for the future
Topics: asthma; asbestos; comfort criteria; construction industry; dust; gases; legislation; mists; respirators; selection of equipment; United Kingdom.
Safety and Health Practitioner, Jan. 1998, Vol.16, No.1, p.54-57. Illus.
Coyne K.M., Johnson A.T., Yeni-Komshian G.H., Dooly C.R.
Respirator performance ratings for speech intelligibility
Topics: comparative study; evaluation of equipment; respirators; speech intelligibility.
American Industrial Hygiene Association Journal, Apr. 1998, Vol.59, No.4, p.257-260. 6 ref.
McCullough N.V., Brosseau L.M., Vesley D., Vincent J.H.
Improved methods for generation, sampling and recovery of biological aerosols in filter challenge tests
Topics: aerosols; air purifying respirators; bacteria; description of technique; evaluation of technique; filtration efficiency; particle size determination; sampling and analysis; test aerosol generation.
American Industrial Hygiene Association Journal, Apr. 1998, Vol.59, No.4, p.234-241. Illus. 25 ref.
Chen C.C, Huang S.H.
The effects of particle charge on the performance of a filtering facepiece
Topics: aerosols; air purifying respirators; electrostatic particulate filters; equipment testing; filtration efficiency; mathematical models; particle size.
American Industrial Hygiene Association Journal, Apr. 1998, Vol.59, No.4, p.227-233. Illus. 16 ref.
Health and Safety Executive
Breathing gas management
Topics: data sheet; diving; oxygen breathing apparatus; safety engineering; self-contained breathing apparatus; underwater breathing apparatus; United Kingdom.
HSE Books, PO Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 1998. 3p. Illus. 6 ref.
Health and Safety Executive
The selection, use and maintenance of respiratory protective equipment - A practical guide
Topics: air purifying respirators; airline respirators; comfort criteria; economic aspects; equipment testing; gas removing respirators; harmful substances; hazard evaluation; hose masks; information of personnel; labelling; legislation; microorganisms; particulate removing respirators; preventive maintenance; protection criteria; radioactive substances; respirators; safety guides; selection of equipment; self-contained breathing apparatus; supplied air respirators; United Kingdom.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 2nd ed., 1998. vi, 75p. Illus. 33 ref. Price: GBP 9.50.
Department of Labor - Occupational Safety and Health Administration (OSHA)
Respiratory Protection; Final Rule [USA]
This final rule (effective 8 April 1998) replaces the respiratory protection standards adopted in 1971. Topics: directive; Fire Service Organization; maintenance and repair; medical examinations; respirators; safety and health training; USA.
Federal Register, 8 Jan. 1998, Part II, Vol.63, No.5, p.1152-1300.
Möritz M., Hake W., Rüden H.
Retention capacity of air filters for microorganisms in ventilation systems
Rückhaltvermögen von Luftfiltern gegenüber Mikroorganismen in RLT-Anlagen [in German]
Topics: bacteria; determination in air; filter testing; filtration efficiency; fungi; microorganisms; particulate filters; ventilation systems; yeast.
HLH - Zeitschrift für Heizung, Lüftung, Klimatechnik, Haustechnik, Mar. 1997, Vol.48, No.3, p.108-113. Illus. 10 ref.
Air purifying respirators against gases and vapours
Atemschutzfilter gegen Gase/Dämpfe [in German]
Topics: air purifying respirators; Austria; dangerous work; data sheet; harmful substances; hazard identification; list of chemical substances; maintenance; protection criteria; TLV list; toxic gases.
Allgemeine Unfallversicherungsanstalt, Adalbert-Stifter-Str. 65, 1201 Wien, Austria, 1997. 41p. Illus.
Better understanding of personal protective equipment (eyes, ears, respiratory tract and head)
Mieux connaître les équipements de protection individuelle (Yeux, oreilles, voies respiratoires et tête) [in French]
Verstandig omgaan met persoonlijke beschermingsmiddelen (Ogen, oren, ademhaling en hoofd) [in Dutch]
Topics: face and eye protection; gas removing respirators; head protection; hearing protection; particulate removing respirators; personal protective equipment; respirable dust; respirators; safety guides; safety helmets; safety spectacles; training material.
PREVENT, rue Gachard 88, bte 4, 1050 Bruxelles, Belgium, 1997. 20p. Illus. 5 ref.
Waldner-Sander S., Wiens H.
Bundesanstalt für Arbeitsschutz und Arbeitsmedizin
Activity-related safety precautions for dealing with filter dust
Tätigkeitsbezogene Schutzmassnahmen beim Umgang mit Filterstäuben [in German]
Topics: carcinogens; description of technique; directive; dust control; exposure evaluation; filter dust collectors; Germany; glossary; irritants; particulate filters; personal protective equipment; short-term exposure; toxic substances.
Wirtschaftsverlag NW, Verlag für neue Wissenschaft GmbH, Bürgermeister-Smidt-Str. 74-46, Postfach 10 11 10, 27511 Bremerhaven, Germany, 1997. ix, 130p. Illus. 16 ref.
Order of 14 October 1997 approving safety standards for work under water [Spain]
Orden de 14 de octubre de 1997 por la que se aprueban las normas de seguridad para el ejercicio de actividades subacuáticas [España] [in Spanish]
Topics: dangerous substances; decompression tables; decompression; deep diving; diving suits; diving; explosion hazards; health hazards; hyperbaric pressure; law; maintenance; Spain; underwater breathing apparatus; work in pressurized atmosphere.
Boletín Oficial del Estado, 22 Nov. 1997, No.280, p.34419-34427.
Johnson A.T., Scott W.H., Coyne K.M., Sahota M.S., Benjamin M.B., Rhea P.L., Martel G.F., Dooly C.R.
Sweat rate inside a full-facepiece respirator
Topics: comfort assessment; heat load; hot workplaces; respirators; skin temperature; sweat rate.
American Industrial Hygiene Association Journal, Dec. 1997, Vol.58, No.12, p.881-884. 18 ref.
Qian Y., Willeke K., Grinshpun S.A., Donnelly J.
Performance of N95 respirators: Reaerosolization of bacteria and solid particles
Topics: aerosols; airborne dust; bacteria; equipment testing; filtration efficiency; respirators.
American Industrial Hygiene Association Journal, Dec. 1997, Vol.58, No.12, p.876-880. Illus. 21 ref.
Health and Safety Executive
Leaflet on selecting respiratory protective equipment for work with asbestos
Topics: asbestos; implementation of control measures; information of personnel; protection criteria; respirators; selection of equipment; supply of personal protective equipment; United Kingdom.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, Dec. 1997. 14p. 13 ref.
Myojo T., Sugimoto M.
Comparative study of challenge aerosols for performance test for dust respirators
Topics: aerosols; air purifying respirators; quartz; sodium chloride; description of technique; dust control; equipment testing; evaluation of equipment; filtration efficiency; Japan; particulate removing respirators; test aerosol generation.
Industrial Health, Oct. 1997, Vol.35, No.4, p.502-507. Illus. 11 ref.
Meyer J.P., Héry M., Herrault J., Hubert G., François D., Hecht G., Villa M.
Field study of subjective assessment of negative pressure half-masks. Influence of the work conditions on comfort and efficiency
Topics: comfort assessment; comfort criteria; conditions of work; equipment testing; leakage testing; respirators; subjective assessment; visual comfort.
Applied Ergonomics, Oct./Dec. 1997, Vol.28, No.5/6, p.331-338. Illus. 28 ref.
Health and Safety Executive (HSE)
SCUBA diving - A quantitative risk assessment
This report examines the principal causes of fatalities in SCUBA (Self Contained Underwater Breathing Apparatus) diving incidents in order to quantify the risks to which divers are exposed. Accident causes include: entanglement and entrapment; rapid ascent and air embolism; loss of consciousness for unknown reasons; reckless diving; solo diving; health prior to diving. The majority of fatalities result from two or more sequential events or contributory causes (a procedural error or equipment failure). Recommendations include adequate diver training and safe diving practices.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 1997. ii, 63p. Illus. Price: GBP 35.00.
Johnson A.T., et al.
Effect of altered vision on constant load exercise performance while wearing a respirator
In a study of the effect of visual acuity on task performance, 10 subjects walked on a treadmill at 75-80% of their maximum heart rates until their voluntary end points. Subjects wore masks of the same kind, each with a different set of clouded lenses. Performance time was not influenced by measured visual acuity; the average performance rating was considered to be influenced by other mask factors, including respiratory stress, thermal stress, and other vision elements. The lack of influence of visual acuity on work performance at this level of work (moderate to heavy) agrees with Performance Rating Table values published previously.
American Industrial Hygiene Association Journal, Aug. 1997, Vol.58, No.8, p.578-582. 19 ref.
Crutchfield C.D., Park D.L.
Effect of leak location on measured respirator fit
In a study to assess how well current respirator fit-test systems detect leakage, known sources of leakage were introduced at three fixed locations on half-mask and full-face respirators mounted on a headform-breathing machine system. Fit-tests were performed with an ambient aerosol system and a controlled negative pressure (CNP) system. The ambient aerosol system detected an average of 37.2% of the known leakage; there were significant differences in leakage measurements as a function of leak location and mask type. The CNP system detected an overall average of 97.9% of the known leakage; results were not affected by leak location or mask type.
American Industrial Hygiene Association Journal, June 1997, Vol.58, No.6, p.413-417. 15 ref.
Cooling the breathing air in an oxygen mask
Sanso kokyūki no kyūki reikyaku ni tsuite [in Japanese]
The temperature of the breathing air in an oxygen mask usually goes up when carbon dioxide in the closed air circuit is absorbed by the chemical sorbent in the system. This temperature rise has a negative effect on the wearer's working capability. Although there are many ways to reduce this temperature rise, use of ice is best because ice has a high heat-absorbing capacity, is inexpensive and is widely available. This paper describes a new design for an ice-cooled system and its performance.
Journal of ISRP Japan Section - Respiratory Protection, 25 Dec. 1996, Vol.11, No.1, p.9-13. Illus.
Brosseau L.M., Traubel K.
An evaluation of respirator maintenance requirements
A survey of 28 U.S. companies using negative pressure air-purifying respirators revealed that although the majority of companies were meeting requirements regarding inspection, cleaning, maintenance and storage of respirators, some improvements were necessary: inspection of all respirator parts should be carried out before each use; replacement parts should be made readily available on site; regular cleaning should be performed; and more hands-on practice with respirators and their maintenance should be incorporated into training sessions.
American Industrial Hygiene Association Journal, Mar. 1997, Vol.58, No.3, p.242-246. 11 ref.
Han D.H., Willeke K., Colton C.E.
Quantitative fit testing techniques and regulations for tight-fitting respirators: Current methods for measuring aerosol or air leakage, and new developments
The principles of operation of quantitative fit testing (QNFT) techniques accepted by the Occupational Safety and Health Administration (OSHA) are explained along with other newly-developed techniques not yet approved. The advantages and disadvantages of each are examined. Emphasis is on negative pressure air-purifying respirators. Requirements and recommendations for fit testing of positive pressure respirators are also discussed, and currently available QNFT standards and regulations are summarized.
American Industrial Hygiene Association Journal, Mar. 1997, Vol.58, No.3, p.219-228. Illus. 85 ref.
Brosseau L.M., Traubel K.
An evaluation of respirator maintenance requirements
A telephone survey of 28 companies using negative-pressure air-purifying respirators revealed that while the majority of companies were meeting requirements for respiratory protection and respirator maintenance, some improvements were necessary: inspection of all respirator parts should be carried out before and after each use; replacement parts should be made readily available on site; regular cleaning should be performed; and more hands-on practice with respirators and their maintenance should be incorporated into training sessions.
American Industrial Hygiene Association Journal, Feb. 1997, Vol.58, No.2, p.116-120. 11 ref.
Mansdorf S.Z., Henry N., Anderson D., Strong M., Rossi D.
The permeation of substituted chlorosilanes through selected protective clothing
The permeation resistance of a range of glove and suit materials against commercially available chlorosilanes was tested by a standard test method. Breakthrough times are listed for each material. Of the glove barriers tested, Viton¿, 4H¿ laminate and Silver Shield¿ provided the best breakthrough resistance, in excess of 6h in most cases. All protective clothing barriers provided at least 8h of breakthrough resistance, although there was evidence of degradation. The selection of protective clothing based on performance against the hydrolysis product (hydrogen chloride) was found not to be valid. It appears that chlorosilanes more closely mimic the permeation behaviour of chlorinated organic compounds, such as carbon tetrachloride.
American Industrial Hygiene Association Journal, Feb. 1997, Vol.58, No.2, p.110-115. Illus. 13 ref.
Cognitive performance during long-term respirator wear while at rest
Reaction time and decision-making speed were assessed in six male and three female subjects during a 10h measurement period either with or without a respirator. Subject anxiety levels and visual tracking ability were also measured. Reaction time and decision-making speed did not differ significantly between control and respirator conditions at any time during the tests. Subject anxiety increased significantly from initial measurements after 8h of testing for each condition, but no differences were observed between conditions. Visual tracking ability was not affected. Respirator wear over a relatively long period under nonexercise conditions should not significantly inhibit cognitive function.
American Industrial Hygiene Association Journal, Feb. 1997, Vol.58, No.2, p.105-109. 20 ref.
Korzec T., Müller B.H.
Cardiopulmonary response to wearing filter respirators
Kardio-pulmonale Beanspruchung durch das Tragen von Atemschutz-Filtergeräten [in German]
Topics: air filtration; air purifying respirators; cardiological effects; experimental determination; particulate removing respirators; physiology of cardiovascular system; pulmonary ventilation; respiratory impairment.
Zeitschrift für Arbeitswissenschaft, 1996, Vol.50, No.3, p.147-153. Illus. 9 ref.
Tetzlaff K., et al.
Pulmonary barotrauma of a diver using an oxygen rebreathing diving apparatus
A case is reported of a healthy male diver who developed clinical symptoms of mediastinal emphysema after performing a dive using a closed circuit oxygen rebreathing apparatus according to normal procedure. Spiral volumetric computed tomography of the chest four days after the incident detected a small subpleural emphysematous bulla next to the left ventricle. In any case of suspected pulmonary barotrauma, computed tomography of the thorax should be performed to evaluate future fitness to dive.
Aviation, Space, and Environmental Medicine, Dec. 1996, Vol.67, No.12, p.1198-1200. Illus. 18 ref.
Tanaka S., Taneka M., Kimura K., Nozaki K., Seki Y.
Breakthrough time of a respirator cartridge for carbon tetrachloride vapor flow of workers' respiratory patterns
Breakthrough times of a commercially-available respirator cartridge packed with a small amount of activated carbon were determined with three different flow patterns: workers' respiratory patterns, conventional steady-state flows, and three standard patterns consisting of square, sine and sawtooth waves. A mechanical breathing simulator was used to reproduce the three standard wave patterns as well as the workers' respiratory patterns, which had been recorded from three workers wearing a gas mask equipped with a respirator cartridge. The breakthrough test was carried out with 300ppm carbon tetrachloride vapour at average flow rates of the respiratory and standard patterns equivalent to the steady-state flow rates. The breakthrough times for the simulated workers' respiratory patterns were shorter than those for a steady-state flow at the equivalent flow rate, and to be as short as those for sine and sawtooth wave patterns. The shorter breakthrough times for the workers' respiratory patterns could be attributed to a faster maximum inspiratory flow rate than that in the case of steady-state flow. This suggests that the transit time of carbon tetrachloride molecules through the thin activated carbon layer of the respirator cartridge may be too short to permit attainment of adsorption equilibrium.
Industrial Health, 22 Apr. 1996, No.34, p.227-236. Illus. 17 ref.
Tanaka S., Haneda M., Taneka M., Kimura K., Seki Y.
Breakthrough times for vapors of organic solvents with low boiling points in steady-state and pulsating flows on respirator cartridges
The breakthrough times of five organic solvents at various concentrations were measured with steady-state and pulsating flows for commercially available respirator cartridges. The relationship between the logarithmic vapour concentration and the logarithmic breakthrough time of each organic solvent showed an inverse correlation in both of the flow patterns. The organic solvents with lower boiling points had the shorter breakthrough times in both flow patterns. The ratios of the breakthrough times for pulsating flow to those for steady-state flow were lower than 0.9 when the vapour concentrations were higher than 600ppm for ethylacetate, methylacetate, acetone and dichloromethane. That is, the breakthrough in the case of pulsating flow tends to occur earlier than in the steady-state case for a highly concentrated vapours of organic solvents with low boiling points.
Industrial Health, 24 Jan. 1996, No.34, p.125-131. Illus. 11 ref.
Yoon Y.H., Nelson J.H., Lara J.
Respirator cartridge service-life - Exposure to mixtures
Expressions developed previously to assess the service-life of respirator cartridges exposed to binary systems were extended to address multicomponent mixtures. The procedure was tested by obtaining experimental breakthrough data for mixtures of compounds with widely varying breakthrough properties. Data showed that as exposure proceeds, a compound that is adsorbed relatively weakly by the carbon bed may be displaced by a more strongly adsorbed component. The approach described accounts for this displacement phenomenon which significantly influences the service-life of respirator cartridges exposed to multicomponent systems.
American Industrial Hygiene Association Journal, Sep. 1996, Vol.57, No.9, p.809-819. Illus. 18 ref.
The assigned protection factor according to ANSI
The American National Standards Institute (ANSI) standard for respiratory protection lists assigned protection factors (APFs) for various respirators. The APFs are based on reviews of workplace or laboratory studies of respirator performance. The APFs are listed, studies used for each type of respirator are described and summary statistics for each study are given. While more research is required on the performance of respirators in the field, the APFs assigned by the ANSI committee appear to be appropriate based on the limited amount of information available.
American Industrial Hygiene Association Journal, Aug. 1996, Vol.57, No.8, p.735-740. 35 ref.
Robbins C.A., Breysse P.N.
The effect of vapor polarity and boiling point on breakthrough for binary mixtures on respirator carbon
The effect of component polarity and boiling point on the adsorption and breakthrough of a vapour in a binary mixture was investigated. Carbon beds were challenged with mixtures of vapours, and vapour concentrations were monitored using gas chromatography. While the polarity and boiling point of the vapours in the range tested appeared to be unimportant in predicting service life, an effect due to vapour boiling point was suggested. The presence of other vapours should be taken into account when estimating the service life of a respirator for a vapour in a mixture.
American Industrial Hygiene Association Journal, Aug. 1996, Vol.57, No.8, p.717-723. 24 ref.
Lemière C., Cloutier Y., Perrault G., Drolet D., Cartier A., Malo J.L.
Closed-circuit apparatus for specific inhalation challenges with an occupational agent, formaldehyde, in vapor form
Since occupational agents responsible for asthma are frequently present in the workplace as vapours, an apparatus was developed for bronchial provocation tests on subjects exposed to formaldehyde and other chemicals in vapour form. This apparatus was assessed in four subjects suspected of having formaldehyde-induced asthma or alveolitis. The instrument consists of four parts: a gas generator, an exposure chamber, a monitor and an automated regulatory system. The concentrations of formaldehyde were increased from 0.5-1mg/m3 to 3mg/m3, without overshooting the concentration of 3mg/m3 (STEL in Canada). It was observed that target concentrations took a few minutes to be reached, but, once they were obtained, delivered concentrations were stable. The described method should be further validated and extended to other occupational agents.
Chest, June 1996, Vol.109, No.6, p.1631-1635. Illus. 17 ref.
Howie R.M., Johnstone J.B.G., Weston P., Aitken R.J., Groat S.
Institute of Occupational Medicine
Workplace effectiveness of respiratory protective equipment for asbestos removal work
This study is a literature review and report of field surveys on the wearing of respiratory protective equipment (RPE) during asbestos removal work. During the surveys, sampling filters were fitted in the RPE facepieces of workers and investigators at different sites. Main findings: the sampling probe may affect the integrity of the facepiece; the probe is not sampling in the correct position; the sampling filter and the samples were contaminated during the fitting and removal of the facepiece. Materials removed included chrysotile, amosite, crocidolite and their combinations. No apparent relationship was observed between ambient fibre concentrations and material type. Fibre concentrations were measured in both dry and wet stripping operations. The consequences of the use of different asbestos removal techniques (manual, power tools, grid blasting) were assessed. In-facepiece fibre concentrations were below the Clearance Limit (0.01 fibres/mL) in 163 out of 182 measurements. A series of recommendations in order to obtain more information on: conditions inside stripping enclosures; areas where airborne fibre concentrations are unacceptably high; prevailing levels of the wearing of respiratory protection equipment; the influence of human factors on the performance of respirators; problem areas where RPE is either not worn at all or is worn improperly.
HSE Books, PO Box 1999, Sudbury, Suffolk CO10 6FS, United Kingdom, 1996. viii, 84p. Illus. 38 ref. Price: GBP 20.00.
Willeke K., Qian Y., Donnelly J., Grinshpun S., Ulevicius V.
Penetration of airborne microorganisms through a surgical mask and a dust/mist respirator
The penetration of bacterial aerosols and spherical corn oil particles through a surgical mask and a dust/mist respirator was evaluated in a test chamber containing the test device mounted on a mannequin. The concentrations of bacteria upstream and downstream of the device were measured with an aerodynamic size spectrometer. The collection efficiency of nonspherical bacteria was always higher than that of the spherical test particles. Penetration of rod-shaped bacteria depends on their aspect ratio. It is projected that a respirator with 90% efficiency against spherical particles will be about 95% efficient against rod-shaped microorganisms such as Mycobacterium tuberculosis.
American Industrial Hygiene Association Journal, Apr. 1996, Vol.57, No.4, p.348-355. Illus. 48 ref.
Crouch K.G., Johnston O.E.
Nitrous oxide control in the dental operatory: Auxiliary exhaust and mask leakage, design, and scavenging flow rate as factors
Local exhaust systems installed in a dental surgery failed to control patient mouth emissions of nitrous oxide. Laboratory testing on a head form, in conjunction with the surgery observations, established that mask leakage due to poor fit was the primary cause of these emissions. An improved mask fit and the addition of a slotted skirt around the outer mask shell individually resulted in greatly reduced leakage rates in the laboratory tests. Also, exhaust systems placed on the chin, on the chest or in the mouth proved effective in capturing mouth emissions simulated by a breathing machine and head form.
American Industrial Hygiene Association Journal, Mar. 1996, Vol.57, No.3, p.272-278. Illus. 19 ref.
Jennison E.A., Odencrantz J.R., Sembower K., Petsonk E.L.
Self-reported use of respiratory protection among a cohort of underground bituminous coal miners
Patterns of self-reported respirator use were analyzed in a cohort of 193 underground bituminous coal miners who were followed for five years. Based on 1370 responses, the mean percentage of time that a respirator was worn was 18.9% for all subjects; 39.8% reported no respirator usage. Face workers reported wearing respirators a mean of 28.1% of the time compared with 9.8% for nonface workers and 3.0% for supervisors. Higher tenure was associated with lower respirator use. Further studies are needed to relate patterns of respirator use to temporal changes in coal mine dust exposure.
American Industrial Hygiene Association Journal, Feb. 1996, Vol.57, No.2, p.191-195. 17 ref.
Myers W.R., Zhuang Z., Nelson T.
Field measurements of half-facepiece respirators - Foundry operations
Workplace protection factors provided by elastomeric and disposable half-facepiece respirators were calculated from the ratio of ambient and in-facepiece concentrations of dust and fume exposures at three foundries. The main components of the airborne exposures were zinc, lead and silicon. The main components of the in-facepiece samples were zinc, chlorine and lead. While significant differences were observed in ambient zinc and lead concentrations among foundries, no significant difference was observed in the in-facepiece concentrations of these elements among foundries. The in-facepiece penetration data clearly indicate that these respirators, when conscientiously used and maintained, and in conjunction with existing controls, provide effective worker protection.
American Industrial Hygiene Association Journal, Feb. 1996, Vol.57, No.2, p.166-174. 13 ref.
Zhuang Z., Myers W.R.
Field performance measurements of half-facepiece respirators - Paint spraying operations
Workplace protection factors were measured for three half-facepiece respirators fitted with combination high-efficiency filter/organic vapour cartridge air-purifying elements. Exposures to aluminium, chlorine, chromium, silicon, strontium and titanium were estimated during aircraft paint-spraying operations. Ambient and in-facepiece concentrations of all elements combined and of titanium and chromium are tabulated along with workplace protection factors by shift, location, worker, respirator and type of paint application. When these respirators were conscientiously worn, used in conjunction with existing controls, and were properly maintained, they ensured an effective protection of workers.
American Industrial Hygiene Association Journal, Jan. 1996, Vol.57, No.1, p.50-57. Illus. 11 ref.
Refining a risk model for occupational tuberculosis transmission
A probability model is presented to describe the variation with time of levels of exposure to Mycobacterium tuberculosis aerosol experienced by health care workers. Based on this model, analytical solutions are presented for an individual worker's cumulative risk of tuberculosis infection, and for the worker population mean cumulative risk of infection, with and without use of respiratory protection. Given exposure estimates and a definition of acceptable risk, the risk equations developed in this analysis may be used to assist in the selection of respiratory protection for health care workers.
American Industrial Hygiene Association Journal, Jan. 1996, Vol.57, No.1, p.16-22. Illus. 18 ref.
Louhevaara V., et al.
Maximal physical work performance with European standard based fire-protective clothing system and equipment in relation to individual characteristics
The aim of this study was to quantify the effects of fire-protective clothing designed to fulfil European standard EN 469 used over standardized (Nordic) clothing and a self-contained breathing apparatus (SCBA) on maximal physical work performance. Twelve healthy firemen aged 26-46 years were examined. The maximal tests without (control) and with the fire-protective clothing system and SCBA were carried out on a treadmill in a thermoneutral environment. When compared to the control test, the decrease in the maximal power output in terms of maximal working time and walking speed averaged 25%, varying from 18% to 34% with the fire-protective clothing system and the SCBA. At maximum, no significant differences were found in pulmonary ventilation, absolute oxygen consumption, the respiratory exchange ratio, heart rate, systolic blood pressure, the rate-pressure product, mechanical efficiency and the rating of perceived exertion between the tests with and without the tested equipment. The reduction in power output was related to the extra mass of the fire-protective clothing and the SCBA. In physically demanding fire fighting and rescue work all possible means to decrease the mass of both the protective clothing and SCBA need to be considered for maintaining sufficient power output.
European Journal of Applied Physiology and Occupational Physiology, 1995, Vol.71, p.223-229. Illus. 21 ref.
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